Searching for New Physics with b→sτ^{+}τ^{-} Processes | JoVE Visualize

Area of Science:

High Energy Physics
Particle Physics
Beyond Standard Model Physics

Background:

Intriguing hints for lepton flavor universality (LFU) violation have emerged in semileptonic B decays, specifically in charged-current (b→cℓ⁻ν̄ℓ) and neutral-current (b→sℓ⁺ℓ⁻) transitions.
Deviations observed in R<0xE1><0xB5><0x83> and R<0xE1><0xB5><0x83>* suggest new physics impacting tau leptons, while LHCb data indicates deviations in b→sμ⁺μ⁻ processes, pointing towards new physics affecting muons.

Purpose of the Study:

To predict the branching ratios of B→Kτ⁺τ⁻, B→K*τ⁺τ⁻, and Bs→ϕτ⁺τ⁻ decays.
To investigate the potential for large LFU-violating effects in b→sτ⁺τ⁻ transitions, considering new physics (NP) explanations for observed anomalies.
To assess the observability of these predicted enhancements at current and future experiments like LHCb and Belle II.

Main Methods:

Calculation of branching ratios for B→Kτ⁺τ⁻, B→K*τ⁺τ⁻, and Bs→ϕτ⁺τ⁻ decays.
Inclusion of NP effects through modifications in Wilson coefficients C<0xE2><0x82><0x99>(ττ) and C<0xE2><0x82><0x8A>(ττ).
Assumption of a common NP explanation for anomalies in R<0xE1><0xB5><0x83>, R<0xE1><0xB5><0x83>(*), and R<0xE1><0xB5><0x8B> to explore LFU violation.

Main Results:

A significant enhancement of b→sτ⁺τ⁻ processes by approximately three orders of magnitude compared to the Standard Model (SM) predictions is found.
Under general assumptions for NP, the predicted branching ratios for B→Kτ⁺τ⁻, B→K*τ⁺τ⁻, and Bs→ϕτ⁺τ⁻ are within the observable range of LHCb and Belle II.
The results suggest that LFU-violating effects in these decays could be substantial.

Conclusions:

The study provides strong theoretical motivation for searching for new physics in b→sτ⁺τ⁻ decays.
Experimental verification of the predicted enhancements would provide compelling evidence for physics beyond the Standard Model.
Future measurements at LHCb and Belle II are crucial for probing these predicted phenomena and potentially discovering new sources of lepton flavor universality violation.